The present invention relates to a novel and useful lighting device having variable light color and light projection direction.
Circadian systems of humans comprise variations and physiology in behavior that are coordinated with a cycle length close to 24 hrs. Circadian rhythms are present even in the absence of periodic environmental stimuli. Circadian rhythm synchronization is achieved by humans through regular exposure to naturally occurring periods of light and darkness.
During daylight hours, non-visual photosensitive cells in the retina respond to light and signal the human body to set, re-set, and adjust the human circadian rhythm. Although human circadian rhythms were once believed to be relatively in-sensitive to light and more sensitive to social cues, it has been found that the human circadian system is as sensitive to light as is the case with other diurnal organisms.
Such non-visual photo sensitive retina cells are particularly sensitive to blue light and to light emanating from above. Consequently, it is believed that exposure to blue light at night may have a negative health impact as a consequence of a delay of the human body to produce melatonin and through changes to other hormone levels. Conversely, light having blue content has been shown to increase alertness and is, thus, beneficial to humans during the day.
Conventional light fixtures having conventional bulbs are generally not able to change the color or the projection direction of the light produced. For example, a typical floor lamp falls in this category. Some light fixtures are manually adjustable in light direction projection or intensity. The latter is achieved by multi stepped reading lamps or by the use of dimming switches. In addition, home automation systems are available to control the intensities of multiple lamps through memory systems or by remote operation.
Recently, lamps having variable color and intensity have become available and may be remotely controlled by means of communication systems, including smartphone applications, internet web pages, or central control hubs. However, such lighting fixtures only offer projection of light in a fixed direction. In addition, such communication controlled lighting systems are subject to the problems of interference and latency.
In the past, many systems for projecting light to aid in the maintenance of a human circadian system have been proposed. For example, U.S. Pat. Nos. 6,686,691, 8,324,808, 8,686,641 and United States Patent Application Publication US2013/0140988, and US2015/0098239 describe lamps use multi-color sources of light such as, LED to produce biologically beneficial light.
U.S. Pat. No. 6,554,439 and United States Patent Application Publications US2060285324, US2009/012,2530, US 2011/0109445, and US2013/0114241 show illumination devices having multiple sources of color lamps mounted on a base and include controllers for operation.
U.S. Pat. Nos. 8,890,435 and 9,095,029 teach light sources having multiple LEDs sources of light of different colors, either formed into a strip or into side-by-side lamps shinning in one direction.
U.S. Pat. Nos. 6,350,275, 6,623,512, 7,679,281, 8,852,254, 9,039746 and United States Patent Application Publications US2004/0249423, US2008/0275533, and US 2009/0326616 reveal light emitting devices that generate multiple colors, usually in the form of LEDs, and are employed to medically treat patients and to reset human circadian rhythm systems.
United States Patent Application Publication US2008/0065177 illustrates a method of maintaining circadian rhythm in a subject by blocking retinal exposure to particular wave-lengths of light by utilizing filters.
U.S. Pat. No. 8,436,556 shows an LED lighting system involving multiple color light sources that are controlled to mimic sunlight on a cloudless day and to direct such light in an upward direction.
U.S. Pat. No. 8,581,520 and United States Patent Application Publications US2012/0306380, and US2013/0214704 describe lighting systems that project light using multicolor light sources in conjunction with natural light or a source of white light.
A lighting system that controls the emanation of light of a certain correlated color temperature and in multiple particular directions would be a notable advance in the field of interior lighting.